Early discharge of patients with presumed opioid overdose: development of a clinical prediction rule

Prediction of naloxone dose in opioids toxicity based on machine learning techniques (artificial intelligence)

BACKGROUND

Treatment management for opioid poisoning is critical and, at the same time, requires specialized knowledge and skills. This study was designed to develop and evaluate machine learning algorithms for predicting the maintenance dose and duration of hospital stay in opioid poisoning, in order to facilitate appropriate clinical decision-making.

METHOD AND RESULTS

This study used artificial intelligence technology to predict the maintenance dose and duration of administration by selecting clinical and paraclinical features that were selected by Pearson correlation (filter method) (Stage 1) and then the (wrapper method) Recursive Feature Elimination Cross-Validated (RFECV) (Stage2). The duration of administration was divided into two categories: A (which includes a duration of less than or equal to 24 h of infusion) and B (more than 24 h of naloxone infusion). XGBoost algorithm model with an accuracy rate of 91.04%, a prediction rate of 91.34%, and a sensitivity rate of 91.04% and area under the Curve (AUC) 0.97 was best model for classification patients. Also, the best maintenance dose of naloxone was obtained with XGBoost algorithm with R2 = 0.678. Based on the selected algorithm, the most important features for classifying patients for the duration of treatment were bicarbonate, respiration rate, physical sign, The partial pressure of carbon dioxide (PCO2), diastolic blood pressure, pulse rate, naloxone bolus dose, Blood Creatinine(Cr), Body temperature (T). The most important characteristics for determining the maintenance dose of naloxone were physical signs, bolus dose of 4.5 mg/kg, Glasgow Coma Scale (GCS), Creatine Phosphokinase (CPK) and intensive care unit (ICU) add.

CONCLUSION

A predictive model can significantly enhance the decision-making and clinical care provided by emergency physicians in hospitals and medical settings. XGBoost was found to be the superior model.

Revive and Refuse: Capacity, Autonomy, and Refusal of Care After Opioid Overdose

Physicians generally recommend that patients resuscitated with naloxone after opioid overdose stay in the emergency department for a period of observation in order to prevent harm from delayed sequelae of opioid toxicity. Patients frequently refuse this period of observation despiteenefit to risk. Healthcare providers are thus confronted with the challenge of how best to protect the patient's interests while also respecting autonomy, including assessing whether the patient is making an autonomous choice to refuse care. Previous studies have shown that physicians have widely divergent approaches to navigating these conflicts. This paper reviews what is known about the effects of opioid use disorder on decision-making, and argues that some subset of these refusals are non-autonomous choices, even when patients appear to have decision making capacity. This conclusion has several implications for how physicians assess and respond to patients refusing medical recommendations after naloxone resuscitation.

Navigating Care Refusal and Noncompliance in Patients with Opioid Use Disorder

BACKGROUND

For many emergency physicians (EPs), deciding whether or not to allow a patient suffering the ill effects of opioid use to refuse care is the most frequent and fraught situation in which they encounter issues of decision-making capacity, informed refusal, and autonomy. Despite the frequency of this issue and the well-known impacts of opioid use disorder on decision-making, the medical ethics community has offered little targeted analysis or guidance regarding these situations.

DISCUSSION

As a result, EPs demonstrate significant variability in how they evaluate and respond to them, with highly divergent understandings and application of concepts such as decision-making capacity, informed consent, autonomy, legal repercussions, and strategies to resolve the clinical dilemma. In this paper, we seek to provide more clarity to this issue for the EPs.

CONCLUSIONS

Successfully navigating this issue requires that EPs understand the specific effects that opioid use disorder has on decision-making, and how that in turn bears on the ethical concepts of autonomy, capacity, and informed refusal. Understanding these concepts can lead to helpful strategies to resolve these commonly-encountered dilemmas.

2023 American Heart Association Focused Update on the Management of Patients With Cardiac Arrest or Life-Threatening Toxicity Due to Poisoning: An Update to the American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care

In this focused update, the American Heart Association provides updated guidance for resuscitation of patients with cardiac arrest, respiratory arrest, and refractory shock due to poisoning. Based on structured evidence reviews, guidelines are provided for the treatment of critical poisoning from benzodiazepines, β-adrenergic receptor antagonists (also known as β-blockers), L-type calcium channel antagonists (commonly called calcium channel blockers), cocaine, cyanide, digoxin and related cardiac glycosides, local anesthetics, methemoglobinemia, opioids, organophosphates and carbamates, sodium channel antagonists (also called sodium channel blockers), and sympathomimetics. Recommendations are also provided for the use of venoarterial extracorporeal membrane oxygenation. These guidelines discuss the role of atropine, benzodiazepines, calcium, digoxin-specific immune antibody fragments, electrical pacing, flumazenil, glucagon, hemodialysis, hydroxocobalamin, hyperbaric oxygen, insulin, intravenous lipid emulsion, lidocaine, methylene blue, naloxone, pralidoxime, sodium bicarbonate, sodium nitrite, sodium thiosulfate, vasodilators, and vasopressors for the management of specific critical poisonings.

Closed-loop wearable naloxone injector system

Overdoses from non-medical use of opioids can lead to hypoxemic/hypercarbic respiratory failure, cardiac arrest, and death when left untreated. Opioid toxicity is readily reversed with naloxone, a competitive antagonist that can restore respiration. However, there remains a critical need for technologies to administer naloxone in the event of unwitnessed overdose events. We report a closed-loop wearable injector system that measures respiration and apneic motion associated with an opioid overdose event using a pair of on-body accelerometers, and administers naloxone subcutaneously upon detection of an apnea. Our proof-of-concept system has been evaluated in two environments: (i) an approved supervised injection facility (SIF) where people self-inject opioids under medical supervision and (ii) a hospital environment where we simulate opioid-induced apneas in healthy participants. In the SIF (n = 25), our system identified breathing rate and post-injection respiratory depression accurately when compared to a respiratory belt. In the hospital, our algorithm identified simulated apneic events and successfully injected participants with 1.2 mg of naloxone. Naloxone delivery was verified by intravenous blood draw post-injection for all participants. A closed-loop naloxone injector system has the potential to complement existing evidence-based harm reduction strategies and, in the absence of bystanders, help make opioid toxicity events functionally witnessed and in turn more likely to be successfully resuscitated.

Impact of the Opioid Epidemic

In recent years the prescription opioid overdose epidemic has decreased, but has been more than offset by increases in overdose caused by fentanyl and fentanyl analogues. Opioid overdose patients should receive naloxone if they have significant respiratory depression and/or loss of protective airway reflexes. Patients who receive naloxone should be observed for recurrent opioid effects. Patients with opioid overdose may be admitted to the intensive care unit for naloxone infusions, treatment of noncardiogenic pulmonary edema, autonomic instability, or sequelae of hypoxia-ischemia or cardiac arrest. Primary and secondary prevention are important to reduce the number of people with life-threatening opioid overdose.

Opioid-Associated Out-of-Hospital Cardiac Arrest: Distinctive Clinical Features and Implications for Health Care and Public Responses: A Scientific Statement From the American Heart Association

Opioid overdose is the leading cause of death for Americans 25 to 64 years of age, and opioid use disorder affects >2 million Americans. The epidemiology of opioid-associated out-of-hospital cardiac arrest in the United States is changing rapidly, with exponential increases in death resulting from synthetic opioids and linear increases in heroin deaths more than offsetting modest reductions in deaths from prescription opioids. The pathophysiology of polysubstance toxidromes involving opioids, asphyxial death, and prolonged hypoxemia leading to global ischemia (cardiac arrest) differs from that of sudden cardiac arrest. People who use opioids may also develop bacteremia, central nervous system vasculitis and leukoencephalopathy, torsades de pointes, pulmonary vasculopathy, and pulmonary edema. Emergency management of opioid poisoning requires recognition by the lay public or emergency dispatchers, prompt emergency response, and effective ventilation coupled to compressions in the setting of opioid-associated out-of-hospital cardiac arrest. Effective ventilation is challenging to teach, whereas naloxone, an opioid antagonist, can be administered by emergency medical personnel, trained laypeople, and the general public with dispatcher instruction to prevent cardiac arrest. Opioid education and naloxone distributions programs have been developed to teach people who are likely to encounter a person with opioid poisoning how to administer naloxone, deliver high-quality compressions, and perform rescue breathing. Current American Heart Association recommendations call for laypeople and others who cannot reliably establish the presence of a pulse to initiate cardiopulmonary resuscitation in any individual who is unconscious and not breathing normally; if opioid overdose is suspected, naloxone should also be administered. Secondary prevention, including counseling, opioid overdose education with take-home naloxone, and medication for opioid use disorder, is important to prevent recurrent opioid overdose.

Comparing mortality and healthcare utilization in the year following a paramedic-attended non-fatal overdose among people who were and were not transported to hospital: A prospective cohort study using linked administrative health data

BACKGROUND

As the overdose emergency continues in British Columbia (BC), paramedic-attended overdoses are increasing, as is the proportion of people not transported to hospital following an overdose. This study investigated risk of death and subsequent healthcare utilization for people who were and were not transported to hospital after a paramedic-attended non-fatal overdose.

METHODS

Using a linked administrative health data set which includes all overdoses that come into contact with health services in BC, we conducted a prospective cohort study of people who experienced a paramedic-attended non-fatal overdose between 2015 and 2016. People were followed for 365 days after the index event. The primary outcomes assessed were all-cause mortality and overdose-related death. Additionally, we examined healthcare utilization after the index event.

RESULTS

In this study, 8659 (84%) people were transported and 1644 (16%) were not transported to hospital at the index overdose event. There were 279 overdose deaths (2.7% of people, 59.4% of deaths) during follow-up. There was no significant difference in risk of overdose-related death, though people not transported had higher odds of a subsequent non-fatal overdose event captured in emergency department and outpatient records within 90 days. People transported to hospital had higher odds of using hospital and outpatient services for any reason within 365 days.

CONCLUSIONS

Transport to hospital after a non-fatal overdose is an opportunity to provide care for underlying and chronic conditions. There is a need to better understand factors that contribute to non-transport, particularly among people aged 20-59 and people without chronic conditions.

Prehospital Naloxone and Emergency Department Adverse Events: A Dose-Dependent Relationship

BACKGROUND

The purpose of this study was to evaluate prehospital and emergency department (ED) interventions and outcomes of patients who received prehospital naloxone for a suspected opioid overdose.

OBJECTIVES

The primary objective was to evaluate if the individual dose, individual route, total dose, number of prehospital naloxone administrations, or occurrence of a prehospital adverse event (AE) were associated with the occurrence of AEs in the ED. Secondary objectives included a subset analysis of patients who received additional naloxone while in the ED, or were admitted to an intensive care or step-down unit (ICU).

METHODS

This was a retrospective, observational chart review of adult patients who received prehospital naloxone and were transported by ambulance to a suburban academic tertiary care center between 2014 and 2017. Descriptive, univariate, and multivariate statistics were used, with p < 0.05 indicating significance.

RESULTS

There were 513 patients included in the analysis, with a median age of 29 years, and median total prehospital naloxone dose of 2 mg. An increasing number of prehospital naloxone doses, an occurrence of a prehospital AE, and a route of administration other than intranasally for the first dose of prehospital naloxone were significantly associated with an increased likelihood of an ED AE. Patients who received < 2 mg of prehospital naloxone had the least likelihood of being admitted to an ICU, whereas patients who received at least 6 mg had a dramatically increased likelihood of ICU admission.

CONCLUSIONS

Our results suggest that an increasing number of prehospital naloxone doses was significantly associated with an increased likelihood of an ED adverse event.

Management of pharmaceutical and recreational drug poisoning

BACKGROUND

Poisoning is one of the leading causes of admission to the emergency department and intensive care unit. A large number of epidemiological changes have occurred over the last years such as the exponential growth of new synthetic psychoactive substances. Major progress has also been made in analytical screening and assays, enabling the clinicians to rapidly obtain a definite diagnosis.

METHODS

A committee composed of 30 experts from five scientific societies, the Société de Réanimation de Langue Française (SRLF), the Société Française de Médecine d'Urgence (SFMU), the Société de Toxicologie Clinique (STC), the Société Française de Toxicologie Analytique (SFTA) and the Groupe Francophone de Réanimation et d'Urgences Pédiatriques (GFRUP) evaluated eight fields: (1) severity assessment and initial triage; (2) diagnostic approach and role of toxicological analyses; (3) supportive care; (4) decontamination; (5) elimination enhancement; (6) place of antidotes; (7) specificities related to recreational drug poisoning; and (8) characteristics of cardiotoxicant poisoning. Population, Intervention, Comparison, and Outcome (PICO) questions were reviewed and updated as needed, and evidence profiles were generated. Analysis of the literature and formulation of recommendations were then conducted according to the GRADE® methodology.

RESULTS

The SRLF-SFMU guideline panel provided 41 statements concerning the management of pharmaceutical and recreational drug poisoning. Ethanol and chemical poisoning were excluded from the scope of these recommendations. After two rounds of discussion and various amendments, a strong consensus was reached for all recommendations. Six of these recommendations had a high level of evidence (GRADE 1±) and six had a low level of evidence (GRADE 2±). Twenty-nine recommendations were in the form of expert opinion recommendations due to the low evidences in the literature.

CONCLUSIONS

The experts reached a substantial consensus for several strong recommendations for optimal management of pharmaceutical and recreational drug poisoning, mainly regarding the conditions and effectiveness of naloxone and N-acetylcystein as antidotes to treat opioid and acetaminophen poisoning, respectively.

Detection-based prioritisation: Framework of multi-laboratory characteristics for asymptomatic COVID-19 carriers based on integrated Entropy-TOPSIS methods

CONTEXT AND BACKGROUND

Corona virus (COVID) has rapidly gained a foothold and caused a global pandemic. Particularists try their best to tackle this global crisis. New challenges outlined from various medical perspectives may require a novel design solution. Asymptomatic COVID-19 carriers show different health conditions and no symptoms; hence, a differentiation process is required to avert the risk of chronic virus carriers.

OBJECTIVES

Laboratory criteria and patient dataset are compulsory in constructing a new framework. Prioritisation is a popular topic and a complex issue for patients with COVID-19, especially for asymptomatic carriers due to multi-laboratory criteria, criterion importance and trade-off amongst these criteria. This study presents new integrated decision-making framework that handles the prioritisation of patients with COVID-19 and can detect the health conditions of asymptomatic carriers.

METHODS

The methodology includes four phases. Firstly, eight important laboratory criteria are chosen using two feature selection approaches. Real and simulation datasets from various medical perspectives are integrated to produce a new dataset involving 56 patients with different health conditions and can be used to check asymptomatic cases that can be detected within the prioritisation configuration. The first phase aims to develop a new decision matrix depending on the intersection between 'multi-laboratory criteria' and 'COVID-19 patient list'. In the second phase, entropy is utilised to set the objective weight, and TOPSIS is adapted to prioritise patients in the third phase. Finally, objective validation is performed.

RESULTS

The patients are prioritised based on the selected criteria in descending order of health situation starting from the worst to the best. The proposed framework can discriminate among mild, serious and critical conditions and put patients in a queue while considering asymptomatic carriers. Validation findings revealed that the patients are classified into four equal groups and showed significant differences in their scores, indicating the validity of ranking.

CONCLUSIONS

This study implies and discusses the numerous benefits of the suggested framework in detecting/recognising the health condition of patients prior to discharge, supporting the hospitalisation characteristics, managing patient care and optimising clinical prediction rule.

How Emergency Physicians Approach Refusal of Observation after Naloxone Resuscitation

BACKGROUND

Patients who are resuscitated with naloxone frequently refuse a period of observation, even though they may be suffering from a variety of medical and psychiatric comorbidities. Emergency physicians (EPs) are then confronted with the challenge of how best to serve patients' interests while respecting autonomy.

OBJECTIVES

We sought to characterize how EPs think about this kind of dilemma and the strategies they use to resolve them.

METHODS

We conducted qualitative semi-structured interviews with a convenience sample of 59 emergency physicians attending the American College of Emergency Physicians' Scientific Assembly in October 2018. Three case vignettes highlighting different clinical and ethical features served as prompts. Interviews were analyzed using a constant comparative method to identify patterns of responses and derive key themes.

RESULTS

Across the vignettes, EPs demonstrated diverse approaches to observation, assessing decision-making capacity and encouraging compliance. Some EPs refused to comply with a patient's wishes even when they had determined a patient demonstrated capacity. Conversely, a few EPs were willing to allow patients to leave the emergency department (ED) without assessing capacity, or despite determining that the patient lacked capacity. Common reasons for complying with patients' demands were concerns about the patients' rights and concerns about the safety of staff. Most physicians interviewed reported no institutional guidelines or education on the topic, and many physicians expressed an interest in providing medication for addiction treatment in the ED.

CONCLUSIONS

EPs approach this clinical and ethical dilemma in widely divergent ways. Consensus about strategies for navigating patients' wishes relative to clinical concerns are needed to help EPs manage these challenging cases.

Naloxone interventions in opioid overdoses: a systematic review protocol

BACKGROUND

North America is in the midst of an unabated opioid overdose epidemic due to the increasing non-medical use of fentanyl and ultra-potent opioids. Naloxone is an effective antidote to opioid toxicity, yet its optimal dosing in the context of fentanyl and ultra-potent opioid overdoses remains unknown. This review aims to determine the relationship between the first empiric dose of naloxone and reversal of toxicity, adverse events, and the total cumulative dose required among patients with undifferentiated opioid overdoses and those with suspected toxicity from ultra-potent opioids. Secondary objectives include evaluating the relationship between the cumulative naloxone dose and toxicity reversal and adverse events, among patients with undifferentiated opioid overdoses and those with suspected toxicity from ultra-potent opioids.

METHODS

To identify studies, we will search MEDLINE, Embase, CENTRAL, DARE, CDAG, CINAHL, Science Citation Index, multiple trial registries, and the gray literature. Included studies will evaluate patients with suspected or confirmed opioid toxicity from undifferentiated opioids and ultra-potent opioids, who received an empiric and possibly additional doses of naloxone. The main outcomes of interest are the relationship between naloxone dose and toxicity reversal and adverse events. We will include controlled and non-controlled interventional studies, observational studies, case reports/series, and reports from poison control centers. We will extract data and assess study quality in duplicate with discrepancies resolved by consensus or a third party. We will use the Downs and Black and Cochrane risk of bias tools for observational and randomized controlled studies. If we find sufficient variation in dose, we will fit a random effects one-stage model to estimate a dose-response relationship. We will conduct multiple subgroup analyses, including by type of opioid used and by suspected high and low prevalence of ultra-potent opioid use based on geographic location and time of the original studies.

DISCUSSION

Our review will include the most up-to-date available data including ultra-potent opioids to inform the current response to the opioid epidemic, addressing the limitations of recent reviews. We anticipate limitations relating to study heterogeneity. We will disseminate study results widely to update overdose treatment guidelines and naloxone dosing in Take Home Naloxone programs.

Hot Off the Press: Hospital Observation Upon Reversal (HOUR) With Naloxone: A Prospective Clinical Prediction Rule Validation Study

This is a prospective observational study looking to validate a previously derived decision rule designed to help safely discharge opioid overdose patients from the emergency department after 1 hour. They included a convenience sample of 538 adult patients who had received naloxone pre-hospital and compared the Hospital Observation Upon Reversal (HOUR) rule with clinical judgement. The primary outcome of interest was a broadly defined composite of adverse events. The HOUR rule had a sensitivity of 84.1% (95% CI 76.2-92.1%) and a specificity of 62.1% (95% CI 57.6-66.5%), which was very similar to clinical judgement. Clinical judgement would have missed 12 adverse events, while the HOUR rule would have missed 13, although most of those adverse events were probably minor.

Hospital Observation Upon Reversal (HOUR) With Naloxone: A Prospective Clinical Prediction Rule Validation Study

OBJECTIVE

St. Paul's Early Discharge Rule was derived to determine which patients could be safely discharged from the emergency department after a 1-hour observation period following naloxone administration for opiate overdose. The rule suggested that patients could be safely discharged if they could mobilize as usual and had a normal oxygen saturation, respiratory rate, temperature, heart rate, and Glasgow Coma Scale score. Validation of the St. Paul's Early Discharge Rule is necessary to ensure that these criteria are appropriate to apply to patients presenting after an unintentional presumed opioid overdose in the context of emerging synthetic opioids and expanded naloxone access.

METHODS

In this prospective, observational validation study, emergency medicine providers assessed patients 1 hour after administration of prehospital naloxone. Unlike in the derivation study the threshold for normal oxygen saturation was set at 95% and patients were not immediately discharged after a normal 1-hour evaluation. Patients were judged to have a normal 1-hour evaluation if all six criteria of the rule were met. Patients were judged to have an adverse event (AE) if they had one or more of the preestablished AEs.

RESULTS

A total of 538 patients received at least one administration of prehospital naloxone, were transported to the study hospital, and had a 1-hour evaluation performed by a provider. AEs occurred in 82 (15.4%) patients. The rule exhibited a sensitivity of 84.1% (95% confidence interval [CI] = 76.2%-92.1%), a specificity of 62.1% (95% CI = 57.6%-66.5%), and a negative predictive value of 95.6% (95% CI = 93.3%-97.9%). Only one patient with a normal 1-hour evaluation subsequently received additional naloxone following a presumed heroin overdose.

CONCLUSION

This rule may be used to risk stratify patients for early discharge following naloxone administration for suspected opioid overdose.

Incidence of mortality due to rebound toxicity after ‘treat and release’ practices in prehospital opioid overdose care: a systematic review

Introduction

Death due to opioid overdose was declared a public health crisis in Canada in 2015. Traditionally, patients who have overdosed on opioids that are managed by emergency medical services (EMS) are treated with the opioid antagonist naloxone, provided ventilatory support and subsequently transported to hospital. However, certain EMS agencies have permitted patients who have been reversed from opioid overdose to refuse transport, if the patient exhibits capacity to do so. Evidence on the safety of this practice is limited. Therefore, our intent was to examine the available literature to determine mortality and serious adverse events within 48 hours of EMS treat and release due to suspected rebound opioid toxicity after naloxone administration.

Methods

A systematic search was performed on 11 May 2017 in PubMed, Cochrane Central, Embase and CINHAL. Studies that reported on the outcome of patients treated with prehospital naloxone and released at the scene were included. Analyses for incidence of mortality and adverse events at the scene were conducted. Risk of bias and assessment of publication bias was also done.

Results

1401 records were screened after duplicate removal. Eighteen full-text studies were reviewed with seven selected for inclusion. None were found to be high risk of bias. In most studies, heroin was the source of the overdose. Mortality within 48 hours was infrequent with only four deaths among 4912 patients ﴾0.081%﴿ in the seven studies. Only one study reported on adverse events and found no incidence of adverse events from their sample of 71 released patients.

Conclusion

Mortality or serious adverse events due to suspected rebound toxicity in patients released on scene post-EMS treatment with naloxone were rare. However, studies involving longer-acting opioids were rare and no study involved fentanyl.

Comparison of lower-dose versus higher-dose intravenous naloxone on time to recurrence of opioid toxicity in the emergency department

INTRODUCTION

The initial dose of naloxone administered to patients who present to the emergency department (ED) with opioid overdose is highly variable. The objective of this study was to determine if the initial dose of intravenous (IV) naloxone given to these patients was associated with the time to recurrence of opioid toxicity.

METHODS

This was a multicenter retrospective cohort study, conducted at two academic EDs in the United States. Consecutive adults who had a positive response to naloxone for opioid overdose in the ED were included. Patients were categorized into two groups based on initial IV naloxone dose administered: 0.4 mg (lower-dose) or 1-2 mg (higher-dose). The main outcome measure was the time to recurrence of opioid toxicity requiring a second dose of naloxone. Secondary outcomes included the need for naloxone continuous infusion and adverse events.

RESULTS

The study included 84 patients with 42 patients receiving lower-dose and 42 patients receiving higher-dose naloxone. Median time to re-dose of naloxone was similar between the lower-dose (72 [IQR 46-139] minutes) and higher-dose (70 [IQR 44-126] minutes) groups (p=.810). There were 12 patients (29%) in the lower-dose group and 17 patients (41%) in the higher-dose group who subsequently required continuous infusions (p=.359). The proportion of patients with adverse events was similar between lower-dose and higher-dose groups (31% versus 41%, p=.495). There was no difference in the incidence of specific withdrawal related adverse effects.

CONCLUSIONS

The initial dose of naloxone given to patients in the ED does not influence the time to recurrence of opioid toxicity.

Safety of a Brief Emergency Department Observation Protocol for Patients With Presumed Fentanyl Overdose

STUDY OBJECTIVE

Fentanyl overdoses are increasing and few data guide emergency department (ED) management. We evaluate the safety of an ED protocol for patients with presumed fentanyl overdose.

METHODS

At an urban ED, we used administrative data and explicit chart review to identify and describe consecutive patients with uncomplicated presumed fentanyl overdose (no concurrent acute medical issues) from September to December 2016. We linked regional ED and provincial vital statistics databases to ascertain admissions, revisits, and mortality. Primary outcome was a composite of admission and death within 24 hours. Other outcomes included treatment with additional ED naloxone, development of a new medical issue while in the ED, and length of stay. A prespecified subgroup analysis assessed low-risk patients with normal triage vital signs.

RESULTS

There were 1,009 uncomplicated presumed fentanyl overdose, mainly by injection. Median age was 34 years, 85% were men, and 82% received out-of-hospital naloxone. One patient was hospitalized and one discharged patient died within 24 hours (combined outcome 0.2%; 95% confidence interval [CI] 0.04% to 0.8%). Sixteen patients received additional ED naloxone (1.6%; 95% CI 1.0% to 2.6%), none developed a new medical issue (0%; 95% CI 0% to 0.5%), and median length of stay was 173 minutes (interquartile range 101 to 267). For 752 low-risk patients, no patients were admitted or developed a new issue, and one died postdischarge; 3 (0.4%; 95% CI 0.01% to 1.3%) received ED naloxone.

CONCLUSION

In our cohort of ED patients with uncomplicated presumed fentanyl overdose-typically after injection-deterioration, admission, mortality, and postdischarge complications appear low; the majority can be discharged after brief observation. Patients with normal triage vital signs are unlikely to require ED naloxone.

Naloxone dosage for opioid reversal: current evidence and clinical implications

Opioid-related mortality is a growing problem in the United States, and in 2015 there were over 33,000 opioid-related deaths. To combat this mortality trend, naloxone is increasingly being utilized in a pre-hospital setting by emergency personnel and prescribed to laypersons for out-of-hospital administration. With increased utilization of naloxone there has been a subsequent reduction in mortality following an opioid overdose. Reversal of opioid toxicity may precipitate an opioid-withdrawal syndrome. At the same time, there is a risk of inadequate response or re-narcotization after the administration of a single dose of naloxone in patients who have taken large doses or long-acting opioid formulations, as the duration of effect of naloxone is shorter than that of many opioid agonists. As out-of-hospital use of this medication is growing, so too is concern about effective but safe dosing.

Outpatient treatment of acute poisoning by substances of abuse: a prospective observational cohort study

Background

Procedures for the clinical assessment of acute poisoning by substances of abuse should identify patients in need of hospital admission and avoid hazardous discharges, while keeping the observation time short. We assess the safety of a systematic procedure developed at the Oslo Accident and Emergency Outpatient Clinic (OAEOC).

Methods

All patients 12 years and older treated for acute poisoning by substances of abuse at the OAEOC were included consecutively from October 2011 to September 2012. Data were collected on pre-set registration forms. Information on re-presentations to health services nation-wide during the first week following discharge was retrieved from the Norwegian Patient Register and from local electronic medical records. Information on fatalities was obtained from the Norwegian Cause of Death Registry.

Results

There were 2343 cases of acute poisoning by substances of abuse. The main toxic agent was ethanol in 1291 (55 %) cases, opioids in 539 (23 %), benzodiazepines in 194 (8 %), central stimulants in 132 (6 %), and gamma-hydroxybutyrate (GHB) in 105 (4 %). Median observation time was four hours. The patient was hospitalised in 391 (17 %) cases. Two patients died during the first week following discharge, both from a new opioid poisoning. Among 1952 discharges, 375 (19 %) patients re-presented at the OAEOC or a hospital within a week; 13 (0.7 %) with a diagnosis missed at the index episode, 169 (9 %) with a new poisoning, 31 (2 %) for follow-up of concomitant conditions diagnosed at index, and 162 (8 %) for unrelated events. Among the patients with missed diagnoses, five needed further treatment for the same poisoning episode, two were admitted with psychosis, one had hemorrhagic gastritis, another had fractures in need of surgery and four had minor injuries.

Conclusion

The procedure in use at the OAEOC can be considered safe and could be implemented elsewhere. The high re-presentation rate calls for better follow-up.

Routine biological tests in self-poisoning patients: results from an observational prospective multicenter study

CONTEXT

Routine biological tests are frequently ordered in self-poisoning patients, but their clinical relevance is poorly studied.

MATERIALS AND METHODS

This is a prospective multicentric observational study conducted in the emergency departments and intensive care units of 5 university and nonuniversity French hospitals. Adult self-poisoning patients without severely altered vital status on admission were prospectively included.

RESULTS

Routine biological test (serum electrolytes and creatinine, liver enzymes, bilirubin, blood cell count, prothrombin time) ordering and results were analyzed. A total of 1027 patients were enrolled (age, 40.2 ± 14 years; women, 61.5%); no patient died during the hospital stay. Benzodiazepine was suspected in more than 70% of cases; 65% (range, 48%-80%) of patients had at least 1 routine biological test performed. At least 1 abnormal test was registered in 23% of these patients. Three factors were associated with abnormal test results: age older than 40 years, male sex, and poisoning with a drug known to alter routine tests (ie, acetaminophen, NSAIDs, metformine, lithium). Depending on these factors, abnormal results ranged from 14% to 48%. Unexpected severe life-threatening conditions were recorded in 6 patients. Only 3 patients were referred to the intensive care unit solely because of abnormal test results.

CONCLUSION

Routine biological tests are commonly prescribed in nonsevere self-poisoning patients. Abnormal results are frequent but their relevance at bedside remains limited.

Flumazenil, naloxone and the 'coma cocktail'

Flumazenil and naloxone are considered to be pharmacologically ideal antidotes. By competitive binding at the molecular target receptors, they are highly specific antagonists of two important drug classes, the benzodiazepines and opioids, respectively. Both antidotes enjoy rapid onset and short duration after parenteral administration, are easily titrated and are essentially devoid of agonist effects. Yet only naloxone is widely used as a component of the 'coma cocktail', a sequence of empirical treatments to correct altered mental status, while experts discourage the use of flumazenil for such patients. This review contrasts the history, indications, published evidence and novel applications for each antidote in order to explain this disparity in the clinical use of these 'ideal' antidotes.

Commentary on Gjersing & Bretteville-Jensen (2015): EMS-treated opioid overdose--an important opportunity for saving lives

Overdose reversal must be seen as an opportunity for intervention because of the elevated risk of death following the event. While emergency medical cardiac arrest care is a poor parallel for opioid overdose, the need for rigorous review and fiscally prudent solutions is similar. Efforts must be made to look for solutions to prevent and treat future overdose specifically in the population that has had an overdose event.

Naloxone--does over-antagonism matter? Evidence of iatrogenic harm after emergency treatment of heroin/opioid overdose

AIM

To analyse drug users' views and experiences of naloxone during emergency resuscitation after illicit opiate overdose to identify (i) any evidence of harm caused by excessive naloxone dosing ('over-antagonism'); and (ii) implications for the medical administration of naloxone within contemporary emergency settings.

DESIGN

Re-analysis of a large qualitative data set comprising 70 face-to-face interviews conducted within a few hours of heroin/opioid overdose occurring, observations from hospital settings and a further 130 interviews with illicit opiate users. Data were generated between 1997 and 1999.

SETTING

Emergency departments, drug services and pharmacies in two Scottish cities.

PARTICIPANTS

Two hundred illicit opiate users: 131 males and 69 females.

FINDINGS

Participants had limited knowledge of naloxone and its pharmacology, yet described it routinely in negative terms and were critical of its medical administration. In particular, they complained that naloxone induced acute withdrawal symptoms, causing patients to refuse treatment, become aggressive, discharge themselves from hospital and take additional street drugs to counter the naloxone effects. Participants believed that hospital staff should administer naloxone selectively and cautiously, and prescribe counter-naloxone medication if dosing precipitated withdrawals. In contrast, observational data indicated that participants did not always know that they had received naloxone and hospital doctors did not necessarily administer it incautiously.

CONCLUSIONS

Opiate users in urban Scotland repeatedly report harm caused by naloxone over-antagonism, although this is not evident in observational data. The concept of contemporary legend (a form of folklore that can be based on fact and provides a means of communicating and negotiating anxiety) helps to explain why naloxone has such a feared reputation among opiate users.

Illicit opioid intoxication: diagnosis and treatment

Opioid intoxications and overdose are associated with high rates of morbidity and mortality. Opioid overdose may occur in the setting of intravenous or intranasal heroin use, illicit use of diverted opioid medications, intentional or accidental misuse of prescription pain medications, or iatrogenic overdose. In this review, we focused on the epidemiology of illict opioid use in the United States and on the mechanism of action of opioid drugs. We also described the signs and symptoms, and diagnoses of intoxication and overdose. Lastly, we updated the reader about the most recent recommendations for treatment and prevention of opioid intoxications and overdose.

A multidisciplinary rehabilitation programme for patients with chronic low back pain: a prospective study

PURPOSE

To examine the effectiveness of a multidisciplinary rehabilitation programme for patients with chronic low back pain in Hong Kong, and to identify factors associated with work resumption.

METHODS

57 men and 8 women aged 20 to 56 (mean, 39) years who had a more than 3-month history of low back pain and were unresponsive to more than 6 months of conventional treatment participated in a 14-week multidisciplinary rehabilitation programme involving physical conditioning, work conditioning, and work readiness. Training protocols entailed flexibility and endurance training, hydrotherapy, weight lifting, and work stimulation. Patients were assessed at baseline (week 1), week 7, week 14, and month 6 with regard to the intensity of low back pain, self-perceived disability, range of lumbar motion, isoinertial performance of the trunk muscles, and depression level. Patient demographics that influenced work resumption were identified using a prediction model. Patients who did and did not return to work were compared.

RESULTS

Of the 54 patients who completed all follow-up assessments, 28 returned to work and 26 did not. The latter was significantly older (37 vs. 42 years, p=0.038) and absent from work longer (11 vs. 22 months, p=0.029) than the former. The rehabilitation programme helped patients regain physical function and the ability to work. Patients who returned to work showed greater improvement in self-perceived disability and physical function.

CONCLUSION

This rehabilitation programme facilitated regain of physical functioning and the ability to return to work. The pre-programme employment status, duration of absence from work, and patient age were the most important predictors for work resumption.

Drugs of abuse: management of intoxication and antidotes

Illicit drug intoxications are an increasing public health problem for which, in most cases, no antidotes are clinically available. The diagnosis and treatment of these intoxications requires a trained clinician with experience in recognizing the specific signs and symptoms of intoxications to individual drugs as well as polydrug intoxications, which are more the rule than the exception. To make the diagnosis, the clinical observation and a urine toxicology test are often enough. Evaluating the blood levels of drugs is frequently not practical because the tests can be expensive and results may be delayed and unavailable to guide the establishment of a treatment plan. Other laboratory tests may be useful depending on the drug or drugs ingested and the presence of other medical complications. The treatment should be provided in a quiet, safe and reassuring environment. Vital signs should be closely monitored. Changes in blood pressure, respiratory frequency and temperature should be promptly treated, particularly respiratory depression (in cases of opiate intoxication) or hyperthermia (in cases of cocaine or amphetamine intoxication). Intravenous fluids should be administered as soon as possible. Other psychiatric and medical complication should receive appropriate symptomatic treatment. Research on immunotherapies, including vaccines, monoclonal and catalytic antibodies, seems to be a promising approach that may yield specific antidotes for drugs of abuse, helping to ameliorate the morbidity and mortality associated with illicit drug intoxications.

Pre-hospital treatment of acute poisonings in Oslo

Background

Poisoned patients are often treated in and discharged from pre-hospital health care settings. Studies of poisonings should therefore not only include hospitalized patients. Aims: To describe the acutely poisoned patients treated by ambulance personnel and in an outpatient clinic; compare patients transferred to a higher treatment level with those discharged without transfer; and study the one-week mortality after pre-hospital discharge.

Methods

A one-year multi-centre study with prospective inclusion of all acutely poisoned patients ≥ 16 years of age treated in ambulances, an outpatient clinic, and hospitals in Oslo.

Results

A total of 3757 health service contacts from 2997 poisoning episodes were recorded: 1860 were treated in ambulances, of which 15 died and 750 (40%) were discharged without transfer; 956 were treated in outpatient clinic, of which 801 (84%) were discharged without transfer; and 941 episodes were treated in hospitals. Patients discharged alive after ambulance treatment were mainly poisoned by opiates (70%), were frequently comatose (35%), had respiratory depression (37%), and many received naloxone (49%). The majority of the patients discharged from the outpatient clinic were poisoned by ethanol (55%), fewer were comatose (10%), and they rarely had respiratory depression (4%). Among the hospitalized, pharmaceutical poisonings were most common (58%), 23% were comatose, and 7% had respiratory depression. Male patients comprised 69% of the pre-hospital discharges, but only 46% of the hospitalized patients. Except for one patient, who died of a new heroin overdose two days following discharge from an ambulance, there were no deaths during the first week after the poisonings in the 90% of the pre-hospital discharged patients with known identity.

Conclusion

More than half of the poisoned patients treated in pre-hospital treatment settings were discharged without transfer to higher levels. These poisonings were more often caused by drug and alcohol abuse than in those who were hospitalized, and more than two-thirds were males. Almost half of those discharged from ambulances received an antidote. The pre-hospital treatment of these poisonings appears safe regarding short-term mortality.

Safe discharge: an irrational, unhelpful and unachievable concept

Emergency doctors often decide whether to advise hospital admission or discharge by assessing whether a decision to discharge home is considered safe. This implies that hospital admission may be recommended on the basis of exceeding an arbitrarily defined risk of adverse outcome, rather than weighing the potential benefits, risks and costs of hospital admission. This approach is likely to lead to irrational decision making, unnecessary hospitalisation and unrealistic expectations regarding risk. Instead of using the concept of a safe discharge, we should take a more rational approach to decision making, weighing the benefits, risks and costs of hospitalisation against a default option of discharge home. Hospital admission should be recommended only if the expected benefits outweigh the risks and can be accrued at an acceptable cost. Guidelines should be developed using this approach and used to promote and support rational decision making.

Recurrent opioid toxicity after pre-hospital care of presumed heroin overdose patients

BACKGROUND

In patients with presumed heroin overdose, the recommended time of observation after reversing heroin toxicity with naloxone varies widely. The aims of this study were to examine the incidence of recurrent opioid toxicity and the time interval in which it occurs after pre-hospital treatment in presumed heroin overdose patients.

METHODS

We undertook a retrospective study in Helsinki (population, 560,000). Records were reviewed from 1 January 1995 to 31 December 2000. Patients included were treated by the emergency medical service (EMS) for a presumed heroin overdose. Patients with known polydrug/alcohol use or the use of opioids other than heroin were excluded. The EMS records were compared with the cardiac arrest database and the medical examiners' records.

RESULTS

One hundred and forty-five patients were included. The median dose of pre-hospital administered naloxone was 0.4 mg. After pre-hospital care, 84 patients refused further care and were not transported to an emergency department (ED). Seventy-one received pre-hospital naloxone, and no life-threatening events were recorded during a 12-h follow-up period in these patients. After pre-hospital care, 61 patients were transported to an ED. Twelve patients received naloxone in the ED for respiratory depression. All had signs of heroin use-related adverse events within 1 h after receiving pre-hospital naloxone.

CONCLUSIONS

Allowing presumed heroin overdose patients to sign out after pre-hospital care with naloxone is safe. If transported to an ED, a 1-h observation period after naloxone administration seems to be adequate for recurrent heroin toxicity.

Naloxone in opioid poisoning: walking the tightrope

Acute opioid intoxication and overdose are common causes of presentation to emergency departments. Although naloxone, a pure opioid antagonist, has been available for many years, there is still confusion over the appropriate dose and route of administration. This article looks at the reasons for this uncertainty and undertakes a literature review from which a treatment algorithm is presented.

The vexatious vital: neither clinical measurements by nurses nor an electronic monitor provides accurate measurements of respiratory rate in triage

STUDY OBJECTIVE

Of all the vital signs, only respiratory rate is still measured clinically in most US triage systems. Previous studies have demonstrated the inaccuracy, poor interobserver agreement, and low variability of routine measurements of respiratory rate. We assess the variability and accuracy of triage nurses' measurements of respiratory rate against a criterion standard. Also, we assess electronic measurement of respiratory rate against the same criterion standard.

METHODS

Consecutive patients presenting to an urban teaching emergency department (ED) were enrolled in this prospective study. Electronic measurement of respiratory rate was recorded throughout the triage encounter when nurses were recording measurements of respiratory rate. Electronic respiratory rate was measured using transthoracic impedance plethysmography. Immediately after each triage evaluation, criterion standard measurements of respiratory rate were made by research assistants using the World Health Organization recommendation of auscultation or observation for 60 seconds.

RESULTS

We enrolled 159 patients. Variability was low for triage nurses' measurements of respiratory rate (SD 3.3) and electronic measurement of respiratory rate (SD 4.1) compared with criterion standard measurements of respiratory rate (SD 4.8; P <.05). Triage nurses' measurements of respiratory rate and electronic measurement of respiratory rate showed low sensitivity in detecting bradypnea and tachypnea. In a Bland-Altman analysis, triage nurses' measurements of respiratory rate and electronic measurement of respiratory rate showed poor agreement with criterion standard measurements of respiratory rate. Subgroup analysis of patients presenting with cardiac and respiratory symptoms yielded similar results.

CONCLUSION

Neither triage nurses nor an electronic monitor provides accurate measurements of respiratory rate in the ED. Emergency physicians should search for new electronic modalities for measuring respiratory rate to bring respiratory rate into line with other vital signs. Emergency physicians should also consider new clinical strategies for measuring respiratory rate.

Patterns of presentation in heroin overdose resulting in pulmonary edema

The study objective was to describe the morbidity of patients presenting with heroin overdose (HOD)-induced noncardiogenic pulmonary edema (NCPE) at an urban ED. A retrospective chart review of patients presenting between 1996 and 1999 with the diagnosis of HOD was conducted. Using a standardized data abstraction form, information on prehospital care, ED care, demographics, and cointoxications was collected. One hundred twenty-five charts (78%) were available for review. Of these, 13 (10%) were diagnosed with NCPE and all were male. In the field, NCPE patients had an average relative risk of 6, a Glasgow Coma Scale of 4, and all needed naloxone. The average admitted duration of use was 2.9 years for those who developed NCPE compared with 13.2 years for those who did not. Five (42%) NCPE patients tested positive for cocaine use and 7 (58%) tested positive for alcohol. In this cohort, the NCPE patients were male and less experienced users with initial low relative risk and Glasgow Coma Scale which demanded prehospital naloxone use. (Am J Emerg Med 2003;21:32-34.

Heroin-related noncardiogenic pulmonary edema : a case series

STUDY OBJECTIVES

To examine the current clinical spectrum of noncardiogenic pulmonary edema (NCPE) related to heroin overdose.

DESIGN

Retrospective chart review of all identified patients from August 1994 through December 1998.

SETTING

Urban academic hospital.

PATIENTS OR PARTICIPANTS

Heroin-related NCPE was defined as the syndrome in which a patient develops significant hypoxia (room air saturation < 90% with a respiratory rate > 12/min) within 24 h of a clinically apparent heroin overdose. This should be accompanied by radiographic evidence of diffuse pulmonary infiltrates not attributable to other causes, such as cardiac dysfunction, pneumonia, pulmonary embolism, or bronchospasm, and which resolve clinically and radiographically within 48 h.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

Twenty-seven patients were identified during this 53-month period, with a majority being male patients (85%; average age, 34 years). Twenty patients (74%) were hypoxic on emergency department arrival, and 6 patients (22%) had symptoms develop within the first hour. One patient had significant hypoxia develop within 4 h. Nine patients (33%) required mechanical ventilation, and all intubated patients but one were extubated within 24 h. Eighteen patients (66%) were treated with supplemental oxygen alone. Hypoxia resolved spontaneously within 24 h in 74% of patients, with the rest (22%) resolving within 48 h. Twenty patients (74%) had classical radiograph findings of bilateral fluffy infiltrates, but unilateral pulmonary edema occurred in four patients (15%) and more localized disease occurred in two patients (7%).

CONCLUSION

NCPE is an infrequent complication of a heroin overdose. The clinical symptoms of NCPE are clinically apparent either immediately or within 4 h of the overdose. Mechanical ventilation is necessary in only 39% of patients. The incidence of NCPE related to heroin overdose has decreased substantially in the last few decades.